"One day I shot an elephant on my pajamas. How he got into my pajamas, I'll never know."
"This report is so simple even a child of five can understand it! Fetch me a child of five."
"We don't have time to dig trenches. We'll have to buy them made. Get tranches this high (points to waist) and our soldiers won't have to wear trousers. On a second thought, get them this high (points to neck) and our soldiers won't need uniforms. Better yet, get them this high (points to above his head) and we won't need any soldiers!"
(as a hotel clerk)
"What? Ice on room 84? Really? Where did you find it? Ohhh, you want some!"
One day, while Groucho was performing on vaudeville, Harpo got into the middle of the performance, following a screaming woman, just to disturb Groucho's performance. Groucho just picked up his pocket clock and said "The three fifteen is right on time."